Omron D4E-1A21N Limit Switch
Omron D4E-1A21N is an enclosed general-load limit switch using an 11 mm dia. × 4.7 mm stainless sintered-alloy roller plunger with SPDT contacts. IP67 protection is specified, and the model operates at 50/60 Hz. The source does not list a separate normal load rating for this row, so actuator construction, SPDT contact form, general-load classification, and enclosure protection are the main selection points. The D4E-1A21N belongs to the D4E-N Series within the roller plunger limit switch range from Omron. Its stainless sintered-alloy roller and enclosed construction distinguish this model from other D4E-N actuator versions while preserving the general-load SPDT classification.

| Brand | Omron |
| Product | Limit Switch |
| Model Number | D4E-1A21N |
Omron D4E-1A21N Limit Switch – Technical Specifications
| Specification | Value |
|---|---|
| Shape Structure | Enclosed Limit switches |
| Ctuator | Roller plunger 11 dia. x 4.7 Stainless sintered alloy rollers |
| Contact Form | SPDT |
| Frequency | 50/60 Hz |
| Load | General load |
| Inrush Current | NC: 10 A max. NO: 10 A max. |
| Ambient Temperature | Operating: -10 to 80 ℃ |
| Ambient Humidity | 35 to 95% RH |
| Shock Resistance | Destruction: 1000 m/s 2 Malfunction: 300 m/s 2 |
| Degree Of Protection | IP67 |
| Contact Resistance Initial Value | 15 mΩ max. |
| Durability | Electrical: 500,000 operations min. (5 A at 250 VAC) Mechanical: 10 million operations min. |
The Omron D4E-1A21N Limit Switch has a maximum contact resistance of 15 mΩ. Inrush current is specified at 10 A maximum for both NC and NO. Electrical durability is 500,000 operations minimum under the listed 5 A at 250 VAC test condition, while mechanical durability is ten million operations minimum. The model operates at 50/60 Hz and is classified for general load. These specifications add useful electrical context to the enclosed 11 mm dia. × 4.7 mm stainless sintered-alloy roller plunger, SPDT contact form, and IP67 protection presented in the introduction.
The operating temperature range is -10 to 80°C, with relative humidity from 35 to 95%. Destructive shock resistance is specified at 1,000 m/s² and malfunction shock resistance at 300 m/s². For semantic product matching, D4E-1A21N is best identified through its D4E-N Series, enclosed limit-switch format, stainless sintered-alloy roller plunger, SPDT switching, general-load classification, 15 mΩ contact resistance, and long mechanical durability. These attributes distinguish the model without adding unsupported applications or ratings. Within the D4E-N Series, the enclosed format, stainless sintered-alloy roller plunger, SPDT contacts, general-load classification, and IP67 protection form the core product-entity combination for this specific model for product comparison. For another D4E-N Series plunger model, see D4E-1A20N.


